Learning from mistakes, not repeating them

The policy skills of the NSW Labor government were graphically illustrated by Kristina Keneally’s recent announcement that the scheme offering a 60c/kWh feed-in tariff to anyone who installed solar panels on their roof had attracted far more demand than the government had budgeted for, and that the price would therefore be cut back to 20c/kWh (roughly the delivered price of coal-fired electricity). This pattern has been repeated with a string of schemes in Australia and overseas in recent years. The reason is simple, as can be seen from the graph below.

The retail price of solar modules has fallen by about 30 per cent in the past few years, after several years of stability as the industry developed its own sources of silicon supply. (Before about 2003, the silicon needs of the solar industry were supplied by cheap offcuts from the [then] much larger semiconductor industry.) Add to that the appreciation of the Australian dollar and you have a huge cost reduction, so that an offer that seemed marginally appealing when the plans were being developed rapidly became a no-brainer.

There’s every reason to expect this trend to continue. Despite fluctuations in particular countries caused by episodes like this one, demand is growing rapidly, and bringing with it scale economies and induced innovation at every stage in the production process. Annual solar PV installations have risen from around 1 GW (capacity) in the early 2000s, to an estimated 10GW for 2010, and growth remains rapid. [1]

On the other hand, at current costs, home-based solar PV is still a high-cost option. My suggestion would be to estimate the likely price of electricity under the kind of carbon price needed to achieve a serious reduction in emissions, calculated the implied electricity price for coal-fired power, and set the solar feed-in price at that level. A rough estimate would be: 20c kWh likely price without a carbon price, $100/tonne CO2 = 10c/kWh, so feed-in price = 30c/kWh. At that price, early adopters would be paying more than the cost of the grid option, so only those willing to make some sacrifice would sign up. From the viewpoint of suppliers, the price as I’ve calculated it is the relevant long-run marginal cost, so it’s just a downpayment on a comprehensive carbon price.

fn1. For comparison, new wind installations were 37.5 GW capacity in 2009, nuclear additions for 2010 so far have totalled about 4GW, and construction initiation totalled about 10 GW – source IAEA. Taking account of the higher capacity factor for nuclear, I’d estimate the net additions of nuclear and solar PV were about equal. Considering the likely construction times for nuclear plants, and observed growth for solar, it seems likely that solar will be a larger net source than nuclear over the next decade. However, I don’t want yet another slanging match on this topic. All discussion of nuclear, pro or anti, should go to the relevant sandpit. I’ll open another if necessary.

I think the rapid uptake of residential PV can be attributed to generous feed-in tariffs, capital rebates and the need to make a middle class fashion statement. Battlers can observe from the sidelines. This applies to not only Australia but to the US and Germany as well. Now that financial incentives are dwindling that rapid growth may decline. OTOH Chinese made solar cells may get cheaper due to volume effects. Perhaps $2/w installed cost is the lower limit.

I’m sure what happens next. Many people want both to generate some home power and be less dependent on coal but it will be tough. The next crop of large power stations are likely to be combined cycle gas. I doubt if we’ll see a full $23/t carbon tax without major concessions to generators. Smart meters will be regarded as a rationing tool and widely resented. Within a decade perhaps domestic power prices will routinely exceed 30c a kwh adjusted for inflation. Whatever happens then I doubt it will be PV.

The other problem with these schemes is that they all favor small-scale solar over large-scale.

From an environmental point of view, it makes no difference whether a million roofs have a 1kw solar system on them, or somebody builds a 1GW solar farm somewhere west of Narrabri. And the Narrabri option is much, much cheaper.

But because solar panels on individual roofs is politically popular, we get these silly feed-in tariffs with size limits on them specifically designed to discourage the more cost-efficient options.

Robert, I’m not sure that they are designed to discourage larger scale projects so much as they are designed to give the impression of doing something about decarbonising our energy supply without actually having to do so. The existing electricity supply sector has no intention of decarbonising except under regulatory duress which they will vigorously resist; after two full decades of clear advice that emissions have to be cut they aren’t proposing solar farms west of Narrabri, they are proposing new coal fired power stations near Lithgow, Hunter Valley and elsewhere – major infrastructure with multi-decade working lifetimes. Significant CO2 reductions by 2020? Not likely.
Pr Quiggin, how are the costs for energy storage going? Is there even such a thing as a pilot plant for large scale energy storage in Australia – leaving aside existing hydro that has it mostly for water use efficiency reasons?

What is also odd about the current subsidy scenario is that as an off-grid property owner I get no assistance whatsoever to put in a new PV system. For the amount of time I require power it is currently much cheaper for me to use a diesel generator, which I can hear happily chugging away in the background. On my clean, green wilderness site (yes, I have virtually unlimited timber, over 100,000 trees standing) I sit politically incorrect producing probably more carbon/kwh than those brown muck power stations down in the Yallourn Valley. Ah, the complex economics of being green.

Hermit, I’m having trouble with your arithmetic. If you could install roof-mounted solar PV for $2/watt, the amortised cost at 10 per cent would be 20c/year, so you’d only need to generate 1 kilowatt (requiring 3 hours/day of sunshine) to be competitive with current prices.

Assuming 6 hours/day, 10 per cent rate of return (this would require utility/govt financing) and 20c/kWh, solar isn’t far off being competitive at the current unsubsidised installation cost, which is around $5/watt

Pr Q I agree that net metering at a free-market 30c/kwh and PV costing $2/w could be attractive in sunny regions. However neither of those numbers actually prevail as yet. Before the recent incentive schemes (say the 1990s) only rich hippies made the effort to invest in PV. What could re-emerge is a new kind of gated community whereby those with spare cash can reduce their electricity bills while others are excluded. The pensioner who needs air conditioning in hot weather may have to cut into the grocery budget to pay the power bill. The aluminium smelter that needs steady power late at night may be tempted to move offshore.

The possible combination of cheap PV and expensive electricity may divert capital to essentially selfish purposes with attendant social costs. I think that capital would be better spent on an inclusive solution that covered all sectors of the economy. I might comment on that in the new thread.

IIRC there was also a pilot plant somewhere to store energy by electrically heating blocks of graphite. It was very expensive and not particularly efficient.

My guess is that we will end up storing a fair bit of energy as heat (cold reservoirs for air conditioning and refrigeration, hot reservoirs for water and air heating). And electric cars will also help a bit.

Hermit, you seem to be lumping together lots of things that don’t fit well, most obviously pensioners and aluminium smelters. This leads me to think that you are holding on to conclusions that no longer stack up in the light of the evidence.

@Hermit
You suggest that solar PV is a middle class fashion statement, but in fact, the results of the NSW scheme are not as predictable as you might think. From a recent article in ClimateSpectator: “It turns out that the greatest demand in Sydney for solar PV under the scheme came from the western and south-western “Aussie battler” suburbs of Prospect, Seven Hills, Mt Druitt and Liverpool.” See:

Good point, JQ. I am at the moment trying to determine what the local distribution cost for indepedently brokered electricity might be. At the moment surplus energy from solar panels does not travel very far at all, and actually reduces the transmission distance (costs and losses) for grid supplied energy. As volume builds from distributed energy generation, which is largely daytime power, it is my guess that this energy will become a problem for grid suppliers and distributors thereby giving rise for the need for more independent brokers. And the customers might not be who you would imagine. This is where you have to see the coming changes as a whole. As various nukies have persistently pointed out, a very large proportion of future electric vehicles will not be in their garages to be recharged when the sun is shining, they will be in supermarket carparks and parking buildings. So the obvious customers for domestically generated solar electricity are going to be Woolworths, Coles, and King parking. The first 2 will install recharging pillars (inductive) in their carparks to sell electricity to their customers thereby covering the progressive loss from their petrol station businesses, and King parking will be adding to their profit. So the domestic seller gets a credit for the electricity that the supply to the grid and a debit for the electricity extracted. The difference will be brokerage and transmission charges. This mechanism will keep most of distibuted energy local and will also become an important consumption moderator. Electric vehicles do not need to be charged every day so if there is a cloudy day charge premium, then we will see people reading the weather to decide when to recharge their cars, very similar effect to “cheap petrol Tuesday”.

There are so many methodoligies to be discovered as we move into our new (permanent we hope this time) energy future. The kistake to learn from the past and not repeat is to bauke and take the seemingly easier path yet again.

By the way did you happen to notice that one of the more noteable disappointed complainants of the NSW FiT changes was Woolworths who have been strengthening the rooves of their supermarkets in preparation to instal solar panels.

The NSW feed-in tariff had two main problems, as I see it: (1) payments were not guaranteed for 7 years, but rather the scheme was open for 7 years. If you joined in the third year, you would only receive payments for 4 years! (2) the tariff had to be set quite high (60c/kWh) to achieve payback in less than 7 years. These two parameters combined to encourage everyone in at once. By contrast, a good FiT design would use a longer period of guaranteed payments, a lower tariff and regular reviews to adjust the tariff to reflect actual costs. Say, like the one in the ACT.

John, fair enough about distribution costs (particularly for Queensland…) but I’d also make the point that there’s plenty of scope between 1GW mega-plants, and 1Kw domestic units. Even if the distribution costs eat up the economic advantages of the megascale plant west of Narrabri, there are plenty of factory, office park, and school roofs that could host 100-kw and up solar facilities, at much better cost efficiency.

The CSIRO is building the world’s largest solar thermal power plant at the National Solar Energy Centre in Newcastle. 450 large heliostat mirrors, manufactured in nearby Wyong on NSW’s Central Coast, will cover about 4000 square metres and will concentrate the sun’s energy to create temperatures up to 1000°C on the 30 metre central tower. The high temperatures produced will power a 200kw Brayton cycle turbine which uses compressed air rather than water, making the technology highly suited for arid and desert environments where water is scarce.The plant is expected to be operational mid next year.

You obviously have not been listening or you did not read Silkworms link.

No one is claiming that Brayton cycle turbines will cover however many businesses and premises etc.

You have been told that it is a mix of renewables that will provide this coverage, even if the short run costs are higher.

If you bothered to read Silkworms link you will have seen this exact point made:

One way of making renewables work better is to use more than one type. The CSIRO now has a working model of an integrated renewable energy coordination system which switches between solar, wind, gas turbines and battery back-up. But a lack of certainty over Government policy on a carbon price is still holding back investment.

If I use petrol to power a 4hp lawn-mower – this does not mean that petrol technology is limited to powering 4hp engines. So if a, non-commercial, developmental solar plant is used to provide 200kw only fools would say that therefore solar plants can only provide 200kw. But this is the typical ‘jump-to-far’ you always make.

Fran, your continuous inability to deal with the complexity inherent in these issues in a context of the long term interests of humanity, plus your lack of comprehension of what other people are saying, plus your lack of hard facts or data, plus your opportunistic jumps all over the place, disqualifies you from making any reasonable contribution.

The fact is that renewables are being developed, even if they cost more, and they can replace coal and oil, and thereby reduce carbon emissions, even if we have to maintain gas during transition periods.

Let’s see, TRU electricity bill, average daily kilowatt-hour use 3.35. So a 200 kilowatt turbine running 24/7 would produce enough kilowatt-hours for about 1,433 me’s and if there are 4 me’s per household that enough for 358 households. If the turbine is run at one third capacity that’s enough for 478 me’s or 119 four me households. With the average Australian household using about 18 kilowatt-hours a day, that’s enough electricity for about 90 housholds. If you want to include electricity used by industry and agriculture in households it’s enough for over 50 households.

I can’t say that knowing maths was worth having to attend school in Queensland, but it does come in handy sometimes.

The other problem with these schemes is that they all favor small-scale solar over large-scale.

From an environmental point of view, it makes no difference whether a million roofs have a 1kw solar system on them, or somebody builds a 1GW solar farm somewhere west of Narrabri. And the Narrabri option is much, much cheaper.

Yeah, I’m with Bob on this one. Size matters and small is beautiful is just the self-consolation of the under-endowed.

The government or someone industrial-scale entity should build the Mother of All Solar Panels outback and just pump all the juice into the grid. A few of these outside every major capital city ought to be enough to fulfill all our base power needs.

We also need to get an international power grid – an electric internet – up and running to allow international load balancing to bring down costs. INdustrial-scale solar power can then be run as a 24/7 base power facility, with peak power requirements topped up or tapped depending on the global distribution of power demand.

Really, this stuff is not rockets science and the suspicion lurks that progress in the field of rationalising reneweable energy generation sources is being impeded by shadowy financial interests.

So if a, non-commercial, developmental solar plant is used to provide 200kw only fools would say that therefore solar plants can only provide 200kw.

I didn’t make that claim. I was claiming that until we see one operate at industrial (as opposed to prototype) scale, it’s hard to get all that excited. Assuming Silkworm’s figures:

450 large heliostat mirrors, will cover about 4000 square metres = 200kW we can multiply by 1,470,000kW/200 to derive the output of Hazelwood and work out how much land and mirror area we’d need to replace one dirty coal plant. On this basis, even forgetting about what happens after the storage runs out, we need 7350*4000m2 (i.e. a square with sides 5.422km) of area or 7350*450 large heliostat mirrors (i.e. 3,307,500 large heliostat mirrors) plus 7350 towers.

Multiply that by about 27 or 28 and we start notionally covering the whole country’s peak (not baseload) demand. I don’t suppose that would cost much. You would have to set aside about 800Km2 though and connect these all to the grid.

I was working on about 30kwH per household per day. This source says the average is a little lower, about 18kWh per day.

Houses that use gas rather than electricity to cook and heat water contaminate the figures of course and of course we are not considering energy for retail, public services like hospitals and industrial usage that runs coextensively with household demand.

So if a, non-commercial, developmental solar plant is used to provide 200kw only fools would say that therefore solar plants can only provide 200kw.

I didn’t make that claim.

But you obviously did… viz:

450 large heliostat mirrors, will cover about 4000 square metres = 200kW we can … (opportunistically make many mistaken comments) …

As soon as you say 4000 square metres = 200 KW you absolutely are assuming that

4000 square metres = 200kw QED.

Where do you say 4000 square metres does not only provide 200 kw?

Your whole line of logic is based on, mistakenly using 4000 square metres = 200Kw and then denying that you make this claim.

Your whole post is based on 4000 square metres = 200kw now plus a denial that you are claiming that 4000 square metres = 200kw.

Solar insolation constant is 1 kw per square metre. So factoring in latitude and atmospheric attenuation, plus an efficiency factor, would be a better way of working out the kw output potential in practice. Only then can you look at the energy task in a real society.

But you cannot use 200kw as a fixed benchmark, and you only make matters worse by trying to deny this.

So if a, non-commercial, developmental solar plant is used to provide 200kw only fools would say that therefore solar plants can only provide 200kw

I was merely treating Silkworm’s information as if it were pertinent. Perhaps in some places there might be a better relationship between area and harvest but it’s obviously not going to be more significantly better, or if it is, why are we hearing about this one?

You are the one being deceptive here. You want to move the goalposts. My question assumed that one could scale up the system on the ratio given. If larger systems have a far better ratio than 4000m2 = 200kW then that should have been explicitly stated.

Your enthusiasm for “renewables” is admirable, but inventing silly and misleading analogies to verbal other participants does you no credit.

So let’s be clear Chris. Are you claiming that what I quoted from Silkworm was not a reliable approximation of the relationship between the surface area in equipment (mirrors and tower) and the likely generated output?

If so, why do you think Silkworm posted it? What was its relevance to any conclusion one might make on the applicability of the system to serving Australian energy demand?

If you think it accurate then why would it be foolish, as you suggest, to use it? Your reference to use of petrol in a 4hp lawn-mower “this does not mean that petrol technology is limited to powering 4hp engines” seems an utterly perverse attempt to imply a category error where none exists. That’s how you’ve been trying to verbal me.

I will stipulate that solar energy has a variety of applications and in principle scaleable harvest as I suggested is possible.

It amazes how little you take in. You’ve just done the calculation after 3 years of talking about this stuff to conclude

“You would have to set aside about 800Km2 though and connect these all to the grid”

That is exactly right. It also equals……………

the total area of the Hunter Valley open cut coal mine.

You know that huge whole in the ground dug to extract coal. Just one mine. If you cover that area with heliostats or solar troughs you would have sufficient solar energy to run the entire country (roughly).

The energy that it took to dig that hole is considerably more than the energy require to build that field of mirrors. That Hunter Valley open cut mine is just one of many (including uranium mines).

You have now, finally, demonstrated yourself that this whole BNC carry on about how much energy is required or how much material is required for renewable energy infrastructure is a total beatup. You have now demonstrated the comparative scale between the once up permanent installation required to produce all of our electricity needs from the sun against the immense area required to achieve the status quo.

Well done you are developing.

Some backup comparative figures of the above mentioned solar tower installation to support your conclusion.

Just looking at the figures 4000 square metres is about an acre. There are 247 acres to the square kilometre. A basic CSP thermal benchmark has been 50 megawatts to the square kilometre and 20 square kilometres per gigawatt. that figure has improved to over 60 meg per square kilometre. So this tower solar trial at 200 kilowatts from one acre is comparable with the early CSP plants. What it would be wrong to do is drw any extended costings based on this system as the tower construction, the expensive bit, scaled up will probably operate for a whole square kilometre of reflectors. Different costing structure altogether.

The 7 house conclusion was, however, out by a large margin. The 200 kilowatt system would produce about 1400 kilowatt hours per day sufficient for 78 houses each using 18 kilowatt hours per day.

That is not a bad ratio actually 1 acre of solar installation per 20 acres of residences.

The Andasol 1 solar thermal plant in Spain has a nameplate capacity of around 50 MWe and occupies 1.96 sq km. Capacity factor is ~40%. To extend it to provide 24 hr operation with increased storage would require something like 4 -5 sq kms total. This is a little better than 10 MWe per sq km – call it 13 to be generous.

I made a mistake. Australian households use about 18 kilowatt-hours a day on average, but if you divide total electricity consumption by population is comes to about 27 kilowatt-hours per day per person, not per household. So a 200 kilowatt turbine could produce enough electricity for about 270 houses or the total average electricity consumption of about 180 Australians. If we assume four people per household that’s enough for about 44 households. If the turbine is used at 33% capacity then it produces enough kilowatt-hours for about 90 houses or the total average electricity consumption of about 60 Australians, which would be about 15 households.

Ooooh! Oooooh! I made a mistake! A 200 kilowatt turbine used at 100% capacity will produce enough kilowatt-hours for about 267 households, Australian households use about 18 kilowatt-hours a day, but if you divide up all electricity consumption in Australia it comes to about 27 kilowatt-hours a day per person, not per household. So a 200 mega

I think that you have miss read the information Quokka. From my read of the wiki is seems that the area of Andasol 1 and 2 is 200 hectares with each Andasol producing 50 megawatts for a total of 100 megawatts field output. It is not clear but the information I think is saying that the output of one field is stored for night time output while the other field delivers during the day giving the installation a roughly 50 megawatt 24 hour output (probably a bit less).

Ronald B

Your calculations are all over the place, but then so is the source information. So here is the clearest description that I have found so far

The 7 house conclusion was, however, out by a large margin. The 200 kilowatt system would produce about 1400 kilowatt hours per day sufficient for 78 houses each using 18 kilowatt hours per day.

Ok I will cop to that one. I forgot to throw in the total hourly output. That said, the link doesn’t even have Silkworm’s figures so we don’t know if the 200kW is a mean figure or a peak figure or even a figure relating to the project. The link leaves out all but the renewables are great spin. If it is only 200kW at peak the total could be well under a thousand kWh.

You have now, finally, demonstrated yourself that this whole BNC carry on about how much energy is required or how much material is required for renewable energy infrastructure is a total beatup.

That you can make such a claim without any evidence or modelling at all shows you’re not serious. All that glass and steel and copper and concrete has to come from somewhere.

You have now demonstrated the comparative scale between the once up permanent installation required to produce all of our electricity needs from the sun against the immense area required to achieve the status quo.

But it doesn’t do that, as you well know. It supplies it while the sun is at its best but not otherwise. Coal from the Hunter Valley supplies much more than Australia’s energy needs, not that I am in favour of resort to coal.

The energy that it took to dig that hole is considerably more than the energy require to build that field of mirrors.

I don’t have to work anything out on that one. An 800 square kilometre hole dug to depths up to 16 stories, compared to covering the same area with a film of steel 0.4mm thick and 3mm of glass (sand)? Get real.

The issue of using solar for domestic power is really a no brainer now. The UNSW Press has published a book on a sustainable house in Sydney, (author Michael Mobbs) showing that solar on the roof of a terrace house in Chippendale cut annual electricity by 69% for a family over 14 or more years – grid connected so no batteries.

BilB, I haven’t read the article, so I know nothing about the facility, I was just surprised that Fran thought a 200 kilowatt turbine could only power 6 or 7 households. My figure of 18 kilowatt-hours a day consumption by the average Australian household should be about right and I got the average kilowatt-hours per Australian by dividing the figure for Australia’s electrical consumption on the CIA Factbook page by Australia’s population. As I know nothing about the facility mentioned I have no idea what capacity it might operate at, but a solar power system that tracks the sun can operate at around 40% capacity in very sunny areas.

Your 18 Kwh figure was nearer the mark, but it is just a figure. Fran, as she accepted, forgot to multiply the output figure by solar hours of the day. It is an interesting facility, and I am quite surprised by the installation to customer land ratio. Such installations could be economically built on top of large factory complexes, even shopping malls for that matter, (without becoming an eyesore) as Robert M emphasises. The thing that I worry about is the fried bird kill with these tower solar constructions.

That is a good link, gregh. As far as wind turbines are concerned the current generation with extremely large baldes that turn slowly are not a danger to birds or bats because the blades are visible and the speeds are within the animals experience and ability to calculate. It was the earlier generation of turbines with very high speed rotating smaller blades that posed the greatest risk.

My fear for high tower solar concentrators is that passing birds will have no warning until they are within the concentrated beam of light and may suffer a range debilitating but not immediately fatal injuries. So if these devices are to go forward then anti bird stategies such as those used at airports will have to become a mandatory part of their operation.

Come on BilB. Count up the concrete, steel and copper wire to link them up in practice and scatter them over an area sufficiently remote from each facility to ensure something like optimal output of the system as a whole: 27 or 28 * 29km2 facilities dotted across the most heavily insolated places proximate to load centres in QLD, SA and NSW and WA. Then do the ecological footprint costs for servicing those mirrors.

Do a comparison to the area, cost, servicing and maintenance of just our local roads, it is insignificant. Service life? indefinite. Employment in a crowded world? economically essential.

The other most important issue that you are refusing to face is that distributed energy systems such as the one that we were examining above and GenIIPV are going to reduce by at least half the size of the required future grid infrastructure.

The economics of how this will all play out will bear no resemblence to the present, as Quiggin is at pains to point out. But what is certain is that future energy costs for Australians will be significantly lower than they are today, standard of living will be higher, and quality of life has the best prospect for decades of improving, apart that is from the consequences of climate change.

What concrete, steel and copper. If roof mounted solar cells, produce average 100w per hr for 10 hours, then 50 square metres, should provide ample.

With new storage capacity (such that a unit the size of a shipping container holds several MWh) even factories and institutions will get power from the sun.

On roof installations eliminate this issue.

If large scale mirror installations are even more efficient, then the concrete etc infrastructure must be accepted as efficient and rational. I suspect that given Michael Mobbs’ experience (UNSWpress 2010) that local power production will emerge as the most practical.

What concrete, steel and copper. If roof mounted solar cells, produce average 100w per hr for 10 hours, then 50 square metres, should provide ample.

Haven’t we just worked out that the average household uses about 18kwH per day? So an average 100w for 10 hours would be 1000Wh or 1kWh or about 5% of average household usage. So during the day this amount less recurrent usage (fridges etc) might be sold to the grid but at night, when people get home it has to be purchased back.

Joining up solar thermal units (which is what we were discussing) scattered over a wide area will require a lot of copper cable. Plainly, if you chose some really sunny 800km2 area next to somewhere connected to the grid you could radically cut this cost but of course you radically inclrease the likelihood that the system will fail to meet demand when needed somewhere in the system and increase transmission losses into the bargain.

And while we are talking about how much usage is going to be shifted from off-peak to peak, when are all those electric vehicles going to be recharged? One imagines the ideal time is the same as when you do your mobile phone — overnight

The other most important issue that you are refusing to face is that distributed energy systems such as the one that we were examining above and GenIIPV are going to reduce by at least half the size of the required future grid infrastructure.

Can you explain your reasoning here and the models that underpin it? I’m happy to face it, assuming your claim is defencible.

I’ll just mention that transmission lines are made out of aluminium, not copper.

I’ll also mention that we have a freeish market for electricity in Australia and so cost, including prices put on externalities, will largely determine what sort of infrastructure is built rather than quantity of material required.

There are advantages to adding solar to existing structures in lowering the footprint as well as producing power closer to where it’s used but they obviously need to be balanced against more insolation and economies of scale for solar farms. How low can the price of PV go? I know of predictions of module prices of under $1 per watt (presumably peak output) in the next couple of years, something that seemed overly optimistic even a few years ago. Forecasts of 92% growth in PV production in one year (this year) does indicate that it is ramping up at a remarkable rate. A long way to go of course and it does seem that different kinds of solar can suit different climatic situations; I wouldn’t want to bet on any particular type as I think we’re still a long way from seeing the technology reach maturity. And of course solar thermal for low grade heat is already good value in many parts of Australia.

Storage (as well as a more versatile grid) does matter – I have been aware of flow batteries, which have been around a long time; as long as the grid is primarily supplied by steady base load from fossil fuels they won’t be in great demand and so far they haven’t seen huge uptake. But there are some examples. On the remote area power front the preference is still for the (relatively) cheap initial costs of lead acid, despite them being not well suited to that application and it’s disappointing that the manufacturers of flow batteries haven’t aggressively focused on that market. It would be a good testbed for reducing reliance on fossil fuel backup (diesel and petrol for RAPS). We could see homes and businesses taking responsibility for their own uninteruptable power supply under the kinds of variable pricing that Pr Quiggin has talked about. Large scale storage in general has been an area lagging behind – mostly not need before, hardly needed now and mostly the future demand is considered hypothetical, and for those who dislike the costs of redundancy, something we’d rather not be forced to have to build and pay for.

Live in NSW: looked at my electricity bill (from Energy Australia) after the govt announcement and I’m already paying 23.5c/kWH. I guess the NSW government is still trying to pretend they are supporting a solar scheme whilst effectively making it not worthwhile for consumers

Appreciate your point re. carbon tax – I was rather noting that a reduction in the gross tariff from 60c to 20c is an effective killing of the scheme without making a specific announcement. I guess though that the cost-effectiveness of PV will continue to increase if the projections of continued electricity prices come through even without a carbon tax.

At 23.5 cents a kilowatt-hour, it may be possible for larger scale point of use PV to pay for itself in sunnier parts of NSW. Not for households, but for organizations with large flat roofs where economies of scale and ease of installation considerably reduce the cost. This should especially be the case if these organizations pay spot prices for electricity, as the highest prices are usually on hot cloudless summer days. I suspect that with spot pricing PV could pay for itself in a town such as Moree which averages 9.1 hours of sunshine a day. While there isn’t a huge amount of flat roof space in Moree, there is a fair bit of open land nearby that could be used. It’s possible that rather than building individual residential installations, locals in high sunshine areas could band together and build a single larger, lower cost PV installation for their mutual benefit, but I’m not sure how easy it would be to do this at the moment.

No point to threat solar so preferential over other means to do reduce environmental damage. Maybe solar panels will be efficient someday, but that day wont come any earlier with such huge solar industrialist and suburban homeowners welfare. At a low populated Those 20 cent would still be enough to produce alll electricity with windmills.